Article by Justin Peters – original source: https://www.forthegospel.org/read/is-having-a-private-prayer-language-biblical?

“For one who speaks in a tongue does not speak to men but to God, for no one understands, but in his spirit he speaks mysteries.” — 1 Cor. 14:2 (Legacy Standard Bible)

One of the most often employed and most convincing arguments marshaled for the charismatic position of a “private prayer language” is 1 Corinthians 14:2. The Apostle Paul says that one who speaks in a tongue speaks not to men but to God, supporting the charismatic belief that the gift of tongues is a private prayer language. The fact that “no one understands” seems to support that this language is not a human language at all but rather a heavenly, angelic one.


Are all “tongues” the same gift?
For this position to hold, it must first be assumed that the gift of tongues in Acts 2 is fundamentally different than the gift of tongues described in 1 Corinthians 12-14. There is complete agreement between charismatics and cessationists that the gift of tongues in Acts 2 involves known human languages. Those languages, 16 of them, are conveniently listed in the text. The argument that the gift of tongues listed in 1 Corinthians does not refer to known human languages is a hard sell, however, given that Luke wrote Acts five years after Paul wrote 1 Corinthians. If the gift in 1 Corinthians was fundamentally different from the gift in Acts, why would Luke, a traveling companion of Paul’s, use the same word for tongues as Paul (glossolalia) and ascribe to the gift the same source (the Holy Spirit) as Paul? It stretches credulity that Luke would not make such a fundamental difference known. The reason he did not is that it is the same gift.


Who is Paul referring to?
So, if the person speaking in a tongue is speaking in a known human language, why would “no one understand”? The “no one” does not refer to all people throughout the world, but only to those in the local Corinthian assembly. No one in the church of Corinth would understand what was being spoken because the message would be in a known language but one unknown to them. This person “speaks to God” because only God understands what is being spoken (He does, after all, know all human languages). This is precisely why Paul stresses the necessity of an interpreter. Paul says that if there is no one to interpret, “let him keep silent” (1 Cor. 12:28). An interpreter, or translator, must translate so that the church can be edified.


What is the purpose of spiritual gifts?
Remember that the purpose of the spiritual gifts is for the edification of the church (1 Cor. 12:7), not for our own private use! We cannot carve out an exception for the gift of tongues and say, ‘This one I’m using for myself.’ That defeats the entire purpose for which the Holy Spirit gives His gifts. There is no record anywhere in scripture of anyone speaking to God in anything but a known human language. We should hasten to point out that this includes the angels and Jesus Himself! So when you pray, pray like the Apostles and Jesus prayed — in a language you actually understand.